Audio power amplifier and audio device

Abstract

The invention discloses an audio power amplifier and an audio device. The audio power amplifier comprises a digital-to-analog conversion circuit, an integral comparison circuit, a power output level circuit, and a feedback circuit, wherein the digital-to-analog conversion circuit converts a digital audio signal into a first analog signal; the integral comparison circuit obtains an analog audio signal according to the first analog signal, a feedback signal and a common-mode voltage signal; the power output level circuit supplies the power by employing a second power supply voltage, and carries out power amplification on the analog audio signal to output a power amplification signal; the feedback circuit generates the feedback signal according to the power amplification signal; the feedback circuit includes a voltage division circuit and a feedback branch, wherein the voltage division circuit carries out voltage division on the power amplification signal, and an obtained voltage division signal is output via a voltage division node; a first end of the feedback branch is coupled to the voltage division node, and the second end of the feedback branch outputs the feedback signal; and an amplitude of the common-mode voltage signal is associated with the second power supply voltage and a voltage division ratio of the voltage division circuit. According to the scheme disclosed by the invention, the audio signal output by the audio power amplifier has a large dynamic range, the circuit area is small, and the cost is low.

Description

technical field [0001] The invention relates to the field of electronic circuit design, in particular to an audio frequency power amplifier and audio equipment. Background technique [0002] Portable smart audio devices, such as smart phones, have more and more integrated functions, making them a personal multimedia terminal integrating communication and social interaction, audio-visual entertainment, and news information. Consumers also have higher requirements for audio volume and sound quality. Audio power amplifiers in audio equipment are generally powered by batteries, such as lithium batteries. Due to the limitation of lithium battery voltage (the power supply voltage range is about 3.3V to 4.35V), the audio power amplifier power rail in audio equipment is only up to 4.35V, and the output peak voltage can be up to about 4V, without obvious truncated distortion. Under the following conditions, for a speaker with an impedance of 8Ω, the output power is up to 1W. In or...

AI Technical Summary

Problems solved by technology

This means that when the second power supply voltage PVDD rises, the first power supply voltage VDD also needs to rise accordingly, then the digital-to-analog conversion circuit 10 and the integral comparison circuit 20 powered by the first power supply voltage VDD work Under high voltage, all internal devices need to be implemented with high-voltage devices, which means high cost and large chip area

[0005] Therefore, the audio power amplifiers in the prior art cannot meet the requirements for chip area and cost while meeting high musical dynamic range.

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